The long term goal of this research is to understand the molecular basis of receptor trafficking in mammalian cells. The goal of this proposal is to study how one type of receptor is collected into a transport vesicle and delivered to another subcellular compartment. Specifically, we seek to understand the mechanism by which a newly discovered protein, TIP47, facilitates the collection of mannose 6-phosphate receptors into transport vesicles that bud from endosomes and carry the receptors to the trans Golgi network. TIP47 recognizes a phenylalanine/tryptophan signal in the cytoplasmic domain of the cation-dependent MPR that is essential for its retrieval from endosomes and delivery to the Golgi. We describe here experiments designed to investigate why mannose 6-phosphate receptors are recognized by a specific trafficking machinery depending upon their intracellular localization. We also propose to continue our analysis of the Rab9 GTPase in terms of how it regulates MPR trafficking. Rab GTPases are believed to function in vesicle docking. We have discovered a novel Rab9 effector, p40, which binds preferentially to the active, GTP-bound form of Rab9. p40 is a highly active transport factor. We propose experiments designed to determine if p40 functions in vesicle docking. These studies have important implications for our understanding of growth control and antigen processing, and will provide fundamental information regarding the mechanism of receptor trafficking in mammalian cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37DK037332-18
Application #
6634919
Study Section
Molecular Cytology Study Section (CTY)
Program Officer
Haft, Carol R
Project Start
1986-07-01
Project End
2004-06-30
Budget Start
2003-07-01
Budget End
2004-06-30
Support Year
18
Fiscal Year
2003
Total Cost
$327,684
Indirect Cost
Name
Stanford University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Purlyte, Elena; Dhekne, Herschel S; Sarhan, Adil R et al. (2018) Rab29 activation of the Parkinson's disease-associated LRRK2 kinase. EMBO J 37:1-18
Li, Jian; Pfeffer, Suzanne R (2016) Lysosomal membrane glycoproteins bind cholesterol and contribute to lysosomal cholesterol export. Elife 5:
Johnson, Tory A; Pfeffer, Suzanne R (2016) Ezetimibe-sensitive cholesterol uptake by NPC1L1 protein does not require endocytosis. Mol Biol Cell 27:1845-52
Pfeffer, Suzanne R (2016) Lipoprotein secretion: It takes two to TANGO. J Cell Biol 213:297-9
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Lee, Peter L; Ohlson, Maikke B; Pfeffer, Suzanne R (2015) Rab6 regulation of the kinesin family KIF1C motor domain contributes to Golgi tethering. Elife 4:
Cheung, Pak-Yan Patricia; Pfeffer, Suzanne R (2015) Molecular and cellular characterization of GCC185: a tethering protein of the trans-Golgi network. Methods Mol Biol 1270:179-90
Lu, Albert; Pfeffer, Suzanne R (2013) Golgi-associated RhoBTB3 targets cyclin E for ubiquitylation and promotes cell cycle progression. J Cell Biol 203:233-50
van Rahden, Vanessa A; Brand, Kristina; Najm, Juliane et al. (2012) The 5-phosphatase OCRL mediates retrograde transport of the mannose 6-phosphate receptor by regulating a Rac1-cofilin signalling module. Hum Mol Genet 21:5019-38

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